Fact: Young women who have heart attacks are twice as likely to die from them as men are.

Fact: You can protect yourself — and you should start right now.

Melissa Oliver was the last person you'd expect to have heart problems. The 35-year-old Indianapolis bank vice president and mother of a toddler was a slight 5'1", 118 pounds. She ran marathons and competed in triathlons. She was never sick and went to the doctor only for annual physicals. So when she felt a painful pressure in the middle of her chest one February afternoon in 2004, she chalked it up to indigestion. She popped some aspirin and a couple of Rolaids and proceeded to conduct a 20-minute conference call in her office. Only then did she call her doctor. He said she was having an anxiety attack and referred her for a cardiac stress test just to ease her mind. Problem solved, right?

Wrong. Before Oliver could even step onto the treadmill in her doctor's office 9 days later, pictures of her heart revealed something shocking: She'd had a heart attack. The tip of one of her arteries was partially blocked, the result of a congenital heart defect aggravated by high blood pressure — possibly dating back to her pregnancy, when she'd had the hypertensive disorder preeclampsia. But then her cardiologist gave her the really terrifying news: She could be headed for another attack, this one much worse than the first. "I couldn't believe it," Oliver says. "I thought I was going for my morning workout and then would be back at the office as usual. Instead, I ended up in the hospital that night and in surgery the next day with four stents in my artery."

As Oliver learned the hard way, you don't have to be old or male for cardiovascular disease to strike. In fact, it's the number one cause of death for American women over 25, killing more of us than all cancers combined. That's nearly 500,000 every year, and 57,000 more women than men. The American Heart Association estimates that almost a third of women have some form of heart disease. Still, most of them — cue that scary music again — don't even know it. And while research shows that women under 50 have fewer heart attacks than men their age, they're twice as likely to die from them. Why? It could be because women who suffer attacks are either sicker or seeking less aggressive treatment for their symptoms.

If all this has your heart beating a little faster, well, a little worry might not be such a bad thing — assuming it makes you start taking steps to prevent heart disease. And you can do just that, since many heart attacks in women are caused by factors like hypertension and high cholesterol that could have been treated or prevented altogether. "It's important to take care of your heart even before you have any symptoms," says Arthur Agatston, M.D., a Miami cardiologist and author of the new book The South Beach Heart Program. "Quite simply, the earlier you start, the easier it is to prevent heart disease."

Luckily, the latest research shows that the road to a healthy heart isn't so rough. Here, eight steps to make sure your beat goes on for a long, long time.